Water treatment device

Abstract

A water treatment system, for example for treating grey water from domestic appliances comprises a water treatment device containing a filter media through which the water passes to remove particulates and bio-matter. The device has a lid provided with a spraying device. The spraying device may, for example, receive treated water along a line, possibly with the addition of an anti-foaming agent. Operating of the spraying device thus serves to collapse any foam generated within the water treatment device. Filter media can be cleaned periodically in a cyclone, after being drawn up through a pipe by means of a jet pump, receiving treated water along a line. Treated water is stored in a storage tank for subsequent use.

The invention claimed is: 
     
       1. A water treatment device comprising:
 a housing having a cylindrical side wall and defining a filter chamber, 
 a filter body comprising a permeable wall which contains a granular filter media and is disposed within the filter chamber, 
 an annular passage defined between the cylindrical side wall of the housing and the filter body, the permeable wall permitting flow from the annular passage into the granular filter media 
 an inlet in the housing for water to be treated, the inlet opening into the annular passage and being disposed so as to create a circulating flow within the housing, 
 a clean water outlet for treated water that has passed through the filter media, 
 an overflow outlet for overflow water, 
 a source of an anti-foaming agent, 
 a spraying device connected to the source of an anti-foaming agent, the spraying device being situated above the filter media for spraying the anti-foaming agent in a direction towards the filter media, wherein 
 the permeable wall is provided with a blocking element preventing flow through the permeable wall at the region of the permeable wall adjacent the inlet. 
 
     
     
       2. A water treatment device as claimed in  claim 1 , in which the filter housing is provided with a lid engaging the side wall. 
     
     
       3. A water treatment device as claimed in  claim 2 , in which the spraying device is supported on the lid. 
     
     
       4. A water treatment device as claimed in  claim 1 , in which the spraying device is connected to receive treated water derived from the treated water outlet, a dispenser for anti-foaming agent being provided for delivering the anti-foaming agent to the treated water supplied to the spraying device. 
     
     
       5. A water treatment device as claimed in  claim 2 , in which the spraying device is connected to receive mains water, a dispenser for anti-foaming agent being provided for delivering the anti-foaming agent to the mains water supplied to the spraying device. 
     
     
       6. A water treatment device as claimed in  claim 1 , in which the overflow outlet is an annular channel disposed above the filter media. 
     
     
       7. A water treatment device as claimed in  claim 1 , in which the annular channel is defined between the side wall and an inner wall of the annular channel. 
     
     
       8. A water treatment device as claimed in  claim 7 , in which the inner wall has an upper edge providing a weir for the overflow of water from the filter chamber into the annular channel. 
     
     
       9. A water treatment device as claimed in  claim 1 , in which a dispensing means for a water treatment agent is provided, the dispensing means comprising a dispensing nozzle disposed to discharge the water treatment agent into the annular passage. 
     
     
       10. A water treatment system comprising a source of water to be treated and a water treatment device, the water treatment device comprising:
 a housing having a cylindrical side wall and defining a filter chamber, 
 a filter body comprising a permeable wall which contains a granular filter media and is disposed within the filter chamber, 
 an annular passage defined between the cylindrical side wall of the housing and the filter body, the permeable wall permitting flow from the annular passage into the granular filter media 
 an inlet in the housing for water to be treated, the inlet opening into the annular passage and being disposed so as to create a circulating flow within the housing, 
 a clean water outlet for treated water that has passed through the filter media, 
 an overflow outlet for overflow water, 
 a source of an anti-foaming agent, 
 a spraying device connected to the source of an anti-foaming agent, the spraying device being situated above the filter media for spraying the anti-foaming agent in a direction towards the filter media, wherein 
 the permeable wall is provided with a blocking element preventing flow through the permeable wall at the region of the permeable wall adjacent the inlet. 
 
     
     
       11. A water treatment system as claimed in  claim 10 , in which a strainer is provided at the inlet of the water treatment device. 
     
     
       12. A water treatment system as claimed in  claim 11 , in which the strainer comprises a chamber divided by a screen into a dirty side and a screened side, the screen being provided with a discharge port exposed to the dirty side and communicating with a drain, the dirty side of the chamber having a hollow core finder which is open to the chamber and is connected to the drain so as to bypass the discharge port. 
     
     
       13. A water treatment system as claimed in  claim 10 , in which the clean water outer of the water treatment device discharges into a collecting tank which is connected to supply a treated water storage tank, a control device being provided for causing the contents of the water storage tank to be discharged to the drain at predetermined intervals.